An optical current monitor for detecting a current traveling through conductive material. The optical current monitor comprises a light source for emitting light at an output level; a lens configured to receive the light; Faraday material positioned near the conductive material and configured to receive light that has passed through the lens, thereby producing rotated light; a polarizer configured to polarize the rotated light; a photodetector configured to receive the rotated light and output a signal as a function of the rotated light; and a feedback system. The feedback system is configured to receive the signal from the photodetector and modify the output level of the light source based on the signal so that the signal remains at a reference level when the current is not traveling through the conductive material.

The optical interferometric sensor device comprises an integrated beam splitter having a first facet and a second facet with optical ports arranged therein. On the beam splitter, the beam splitting junctions as well as the optoelectronics-side ports and the sensing-side port are arranged with a mutual displacement along the direction of the first facet. This displacement reduces undesired interference effects caused by stray light. Also, a quarter-wave retarder is provided in a recess of the beam splitter with layers of soft adhesive adjacent to it in order to reduce stress.

Techniques for reducing interference with sensor (light) signals and measurement in polarimetric fiber optic sensors from undesired effects of current and vibrations on light signals carried in fiber optic cables are presented. A sensor system comprises a first depolarizer associated with a fiber optic cable and in proximity to a light source that provides a light signal to such cable. First depolarizer depolarizes the light signal to produce a first depolarized light signal output to another portion of the fiber optic cable that can be wrapped around or associated with a conductor cable or ground cable. To reduce undesired polarizing effects on the first depolarized light signal due to current or vibrations from the conductor cable or ground cable, the system comprises a second depolarizer that depolarizes the (re)polarized light signal to produce a second depolarized light signal suitable for use in sensing current or voltage after additional processing.

A device for installing an all fiber optoelectrical transducer on the base of a pin insulator column, such that the device mounts to the insulator pin column in a bushing style of concentric attachment and enables retrofits of said device to existing transmission & distribution bushing insulator equipment. A rigid and solid mechanical support region contains a hollow bushing attachment point at a center location, and radiates outward and bonds solidly and statically to a hollow toroidal conduit, which houses optical wave guides, terminating at auxiliary connection ports, located on the exterior of the hollow toroidal conduit region, while hollow conduit support arms extend from the exterior conduit ring to a power conductor region, and integrate with optical connection ports located on static support stands, where the optical ports interface with a detachable and flexible fiber loop transducer, which surrounds an energized power conductor.

A device for installing an all fiber optoelectrical transducer on the base of a pin insulator column, such that the device mounts to the insulator pin column in a bushing style of concentric attachment and enables retrofits of said device to existing transmission & distribution bushing insulator equipment. A rigid and solid mechanical support region contains a hollow bushing attachment point at a center location, and radiates outward and bonds solidly and statically to a hollow toroidal conduit, which houses optical wave guides, terminating at auxiliary connection ports, located on the exterior of the hollow toroidal conduit region, while hollow conduit support arms extend from the exterior conduit ring to a power conductor region, and integrate with optical connection ports located on static support stands, where the optical ports interface with a detachable and flexible fiber loop transducer, which surrounds an energized power conductor.

The invention relates to a spliced optical fiber comprising a first and second polarization-maintaining optical fiber connected at ends by splicing; to fiber optic current sensors; and to a method for protecting the spliced optical fiber against mechanical stress and/or humidity. A protection tube is arranged around the spliced optical fiber in a splice section of the spliced optical fiber. A first and second end of the protection tube is sealed to the spliced optical fiber by first and second sealing arrangement for protecting the splice.

The invention relates to a spliced optical fiber comprising a first and second polarization-maintaining optical fiber connected at ends by splicing; to fiber optic current sensors; and to a method for protecting the spliced optical fiber against mechanical stress and/or humidity. A protection tube is arranged around the spliced optical fiber in a splice section of the spliced optical fiber. A first and second end of the protection tube is sealed to the spliced optical fiber by first and second sealing arrangement for protecting the splice.

This patent document discloses techniques and devices for sensing or measuring electric currents and/or temperature based on photonic sensing techniques. The optical sensors for sensing the current or temperature can be configured as a polarization-insensitive optical sensor in either an optical transmissive configuration or an optical reflective configuration.

A system for measuring a cathode current includes a conducting bar and a current measuring device. The conducting bar has a rectangular plate-like structure, and a first end of the conducting bar is vertically cut to form a plurality of long teeth. The plurality of long teeth are equally spaced at the first end of the conducting bar. The number of the plurality of long teeth is equal to the number of cathodes. The upper surface of each of the long teeth may include a raised conductive contact. Each of the conductive contacts is connected with one cathode of an upstream slot. A second end of the conducting bar is connected with a downstream slot, and the second end of the conducting bar is one end opposite to the first end. The current measuring device is disposed on the conducting bar and used for measuring the current of each cathode.

A system for measuring a cathode current includes a conducting bar and a current measuring device. The conducting bar has a rectangular plate-like structure, and a first end of the conducting bar is vertically cut to form a plurality of long teeth. The plurality of long teeth are equally spaced at the first end of the conducting bar. The number of the plurality of long teeth is equal to the number of cathodes. The upper surface of each of the long teeth may include a raised conductive contact. Each of the conductive contacts is connected with one cathode of an upstream slot. A second end of the conducting bar is connected with a downstream slot, and the second end of the conducting bar is one end opposite to the first end. The current measuring device is disposed on the conducting bar and used for measuring the current of each cathode.